A Hackensack man was reported missing after he walked into the Hackensack River on Sunday afternoon and started swimming, struggling to keep his head above water.

As his friends tried to stop him, the unidentified man walked behind the Heritage Diner and waded into the Hackensack River, police said in a statement. The man started swimming toward Bogota, gradually appearing to struggle before his friends lost sight of him beneath the water, police said in a statement.

As a precaution, Hackensack Police has declined to identify the missing man until he is found.

The man's two friends searched the area for more than an hour to no avail, sparking a tri-borough search effort between Hackensack, Maywood and Bogotoa authorities that even brought the State Police's helicopter "North Star."

Despite the combined efforts of the police departments, the man was not found as of Monday afternoon.

On Monday afternoon, Hackensack Fire Department's rescue boat embarked on another search of the river, carrying divers to scour the water, said Aquila.